The present invention relates to a storage control apparatus and a storage control method, and particularly to a storage control apparatus that charges a storage element using a power generating element and a processing method therefor.
Development of sources of clean energy that do not emit carbon dioxide and pollutants has been demanded as an environmental protection measure. Among them, solar power generation and wind power generation have increasingly proliferated in recent years. Particularly, solar power generating devices are being proliferated in general households, because of decreases in manufacturing costs of solar batteries (solar panels) disposed on roofs of houses and increases in power generation efficiency thereof. In addition, downsizing of solar batteries has advanced and mobile phones equipped therewith are now being sold.
Solar batteries have a property that is different from a property of a constant voltage source such as a dry cell. That is, the solar batteries have a property as a current source that depends on a voltage between terminals. For this reason, a voltage of a load connected to a solar battery needs to be matched with a maximum power point voltage of the solar battery to obtain a maximum output from the solar battery. In a current/voltage characteristic of the solar battery, there is only one maximum power point (MPP) at which power is maximized. However, because the current/voltage characteristic of the solar battery changes depending on an environment such as the illumination or the temperature, control to obtain the MPP voltage needs to be performed when a solar battery connection apparatus operates. The control to obtain the MPP when the apparatus operates is called maximum power point tracking (MPPT) control.
Various methods have been suggested as methods for executing the MPPT control. However, methods that are used in a direct-current path are roughly divided into two methods, i.e., a method of switching serial or parallel connection of a plurality of solar batteries (for example, refer to Patent Literature 1) and a method of controlling a switching-type DC-DC converter and obtaining an MPP (for example, refer to Patent Literature 2).